I was having a lively discussion with my training partners while we were trying to schedule our morning bike ride last weekend. I was begging for us to go earlier, to beat the heat. My friend replied I have to race in the afternoon, so I need to get used to this crap (heat and humidity)!’ And so we went and rode 60+ miles starting at 9 AM when the heat and humidity were getting close to their highest.
I also work with a triathlon coach in Michigan, who posted that he was not going to train to beat the heat like he usually does, but go and do his long 17 mile run in the afternoon similar to when he will be running during his upcoming Ironman race. It all makes sense as it takes time for the body to adjust to the heat and humidity (10 days for most) and even then, most of us try to get up early to train to beat that heat. When in reality, we should train IN the heat. 
I am sure it will feel terrible the first couple of times you go, but as you get used to that heat and humidity, your body will need less additional electrolytes to handle that heat.
Come race day, you will be happy you did not train to beat the heat, but trained IN the heat. During that training, watch for signs of dehydration (earlier post lists those in detail), really pay attention to those signs even if slight. Do not be afraid to take in more electrolytes to help the body adapt. Electrolytes help more than adding food especially when hot and humid. The body will get used to the heat and humidity, but only if you train in it. Do not beat the heat in all of your training sessions. But do weigh yourself before and after so you can track how much weight you lost. If you lose more than 1-2% of your body weight in water, that means you are severely dehydrated! and this can be a really serious issue.
The goal is to keep that loss to less than 1%, preferably even .5%! If you weight 140 pounds, that is less than 1 pound(0.7). 2% is almost 3 pounds. If you weight 200 pounds, 1 pound is .5% and 4 pounds is 2%. Last two weekends I saw posts on Facebook where some lost 8 pounds on their 6 hour ride, or 8 pounds on a 16 mile run. Hmm, do they need more fluids? Or do they need more electrolytes (like FIZZ or Endurolytes) to keep the water where it should be? This is where training comes into play and learning how to minimize fluid loss in excessive heat and humidity. Your fatigue might be from dehydration rather than a lack of fuel. 1% dehydration and your performance drops 10-14%. At 4% dehydration, you can pass out and go into a coma. You are risking heat stroke, too where the body can no longer cool itself and stops sweating. Obviously none of these is what we want to experience. So we need to allow the body to acclimate to the conditions, but until it does, we need to be diligent with providing the needed electrolytes and fluids the body needs to keep it working right.
Heat and humidity can kill, which is why there are heat advisories. But you can be smart by doing some of your training in that heat to acclimate, using the right amount of fluids and electrolytes to help your body cope with heat and humidity. Weigh yourself before and after to find out your fluid losses, and make adjustments based on that. If your races are later in the day like they frequently are for cycling races, or your are training for an Ironman, or 70.3, it may make sense not to beat the heat and train in the heat of the day.
Joanna Chodorowska, BA,NC is a sports nutrition coach with Nutrition in Motion, LLC helping athletes use real food to provide real results and performance. She can help you learn your signs of dehydration so you can better acclimate and recover faster. Just today, she received an email from a client who seemed dehydrated. With Joanna’s recommendation, client reported that the headache and fatigue subsided, and the client was able to ride 75 miles comfortably that afternoon after their session. If you have questions about sports nutrition programs or topics, please contact Joanna at www.-n-im.net or [email protected].
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